Article Index

This page lists all of the abstracts for the Spring 2014 colloquium series. For dates and speakers, see Colloquium.

"Speeding up and slowing down light, can quantum information survive?," Tuesday, January 28, 1:30pm, MH 606


Ryan Glasser, National Institute of Standards and Technology

Entanglement is now a well-known phenomenon, and has long been thought to play a vital role in quantum information and communication protocols.  Thus, much theoretical and experimental work has been done to investigate the fundamental properties of entanglement.  In this talk I will present recent experimental work investigating the behavior of an entangled state of light after part of it passes through so-called "fast" or "slow" light media.   A four-wave mixing process in warm atomic vapor is used to both generate an entangled state of light, as well as produce a medium exhibiting slow- and fast-light properties.  Differences in the behavior of the entanglement and quantum information after propagating through such dispersive media will be highlighted.

"How to make a molecular movie," Thursday, January 31, 1:30pm, MH 606

Daniel Rolles, Deutsches Elektronen-Synchrotron (DESY)

Taking a movie of a chemical reaction with atomic resolution? Watching the making and breaking of chemical bonds in real time? Continuing technical advances in the creation of (sub-) femtosecond pulses with optical lasers, relativistic electron guns, and X-Ray Free-Electron Lasers have turned the vision of “recording a molecular movie” with femtosecond temporal and atomic scale structural resolution into a realistic scenario. In this talk, I will discuss recent experiments aimed at visualizing nuclear and electronic dynamics during (photo-)chemical reaction. They open up an exciting new field at the borderline between atomic & molecular physics and physical chemistry which promises to have a profound impact on our understanding of chemical reaction dynamics.
Daniel studied physics at the University of California, Berkeley, and at the Technical University Berlin, Germany, where he earned his Ph.D. in atomic and molecular physics in 2005. After three years as a post-doc and Humboldt fellow at the Lawrence Berkeley National Laboratory, he joined the Max Planck Advanced Study Group at the Center for Free-Electron Laser Science in Hamburg, Germany. Since 2013, he is leading a research group at DESY and Göttingen University, where he is pursuing his dream of “shooting a molecular movie”.

"Spin dynamics in an ultracold sodium quantum gas," Tuesday, February 4, 1:30pm, MH 606

Arne Schwettmann, JQI/NIST/University of Maryland

Ultracold atomic gases provide a fascinating window into the quantum world, presenting us with macroscopic quantum objects to probe and investigate. In this talk, I will first discuss the experimental techniques we use to cool a cloud of sodium atoms in an optical trap to nanokelvin temperatures, at which point it forms a giant matter wave known as spinor Bose-Einstein condensate (BEC). Compared to a scalar BEC, where only one atomic spin state is present, the spinor BEC has the advantage that all atomic spin states are trapped and overlapping. This allows us to investigate the population oscillations driven by coherent spin-changing collisions. I will then present our recent observation of such spin dynamics in the thermal sodium gas, as well as discuss our progress towards implementing a matter-wave interferometer and phase-sensitive matter-wave amplifier in this system.

"Novel Techniques in Electron Scattering Physics," Thursday, February 6, 1:30pm, MH 606

Leigh Hargreaves, California State University - Fullerton

Collisions between electrons and neutral atoms or molecules play driving roles in the chemistry of a wide range of technological and natural environments. These include plasma manufacture of silicon devices, laser and gas discharges, auroral phenomena and medical techniques for treatment of cancer patients. While electron collisions research has long been at the forefront of technological innovations in these (and many other) areas, current experimental techniques remain limited in the targets processes they can consider, largely limited to targets with large vapor pressures and/or large cross sections. In this talk, I will describe new experimental techniques that will open up new avenues of research in scattering physics, primarily based around experiments using multi-hit detection imaging, magnetic guiding fields and time-of-flight energy detection. I will also discuss the application of these techniques towards a new experimental program considering biologically important molecules and neutral radicals.

Dr. McConkey (grand‚Äźdescendant of Lord Rutherford) will talk about a very important project he started in the early 60’s to characterize the Aurora Borealis.